A zombie falls in love with a human and this triggers his heart/blood pumping as well as him being alive. Other zombies witnessing the love begin to get their heart/blood pumping as well effectively curing zombie-ism
That sounds like a great movie right. Original! And very cleverly written ONLY the execution was subpar. How/why he falls for her is crap. And her reaction initially was crap. I don't want to give it away, but this is one of those movies you'll be glad you saw. You probably won't see it again because of those major things, but still glad you viewed it once.